Kotakuite Zhabin points out that the Playstation Store is currently down for "maintenance." While this typically wouldn't be really worth a post, the timing does lend itself to vast amounts of speculation. Could it be that they took the store down to pack it full of trailers, demos and screens from E3? Or maybe it's down tonight so they can prep some new Killzone 2 information, since the Killzone 2 event is this evening.
Personally, I'm holding out hope that it's down because they're preparing to unveil and roll-out a new store with downloadable movies, music and television for both the PS3 and PSP... I also still believe in Santa Clause, so don't listen to me.